Abstract: The core structure of membrane lipids of archaea have some unique properties that permit archaea to be distinguished from the others, i.e., bacteria and eukaryotes. Di-geranylgeranylglyceryl phosphate synthase (DGGGPS), which catalyzes the transfer of a geranylgeranyl group from geranylgeranyl diphosphate to geranylgeranylglyceryl phosphate, is involved in the biosynthesis of archaeal membrane lipids. Our laboratory already cloned, expressed and purified the geranylgeranylglyceryl phosphate synthase (GGGPS) from Thermoplasma acidophilum and reported. The second enzyme in the archaeal membrane lipid biosynthesis DGGGPS has not been cloned and purified from archaea yet. In this work, we cloned the gene encoding DGGGPS after PCR amplification of the gene from genomic library of Thermoplasma acidophilum. The cloned genes were subcloned into a high-expression vector and expressed in the cell of E. coli C41(DE3). The membrane protein was solubilized by 2% n-Octyl- β-glucopyranoside. Then the protein was then purified by heat treatment, DEAE-sepharose and Resource Q column chromatography. The protein gave single band on SDS-PAGE analysis. The molecular mass of 31 KDa was obtained by SDS-PAGE which is full agreement with the DNA sequence. The optimum temperature and pH of the purified protein was 65°C and pH 7.0, respectively.